Sorption Preconcentration of Volatile Organic Compounds in Air Analysis with a Change in the Configuration of the Sorption Layer in a Transition from Sorption to Thermal Desorption

A scheme is proposed for the rapid dynamic sorption preconcentration of volatile organic compounds in the gas chromatographic analysis of air, based on a change in the configuration of the sorption layer in a transition from the sorption to the thermal desorption of analytes. The sorption extraction of analytes is carried out in a wide sorption column, which ensures high flow rates of the analyzed air at relatively small pressure drops created by typical electric aspirators. Then the sorbent is poured into a narrow column, which ensures rapid heating and the minimal blurring of analyte zones in the thermal desorption. The analytical capabilities of the proposed scheme, which makes it possible to reduce the duration of the stage of the sorption preconcentration of analytes by a factor of 3–4, is illustrated on an example of the sorption preconcentration of methanol and phenol using carboxene 1000 and carbopak C, respectively.